Using ComponentSpace SAML to sign and post request - saml-2.0

Question

I am using component space libraries to create SAML request and sign it then post it to URL, However request is not posting successfully because i need to use RSA algorithm key but so far i found that it is not available in SamlKeyAlgorithm also i need to change the Key size to 2048 below are my method that i used to send the request.
private void SendTawtheeqRequest()
{
string ConsumerServiceUrl = "https://tawtheeq.sa:8443/identity-gateway-test/ReceiveSAMLRequest";
// Create a SAML response object.
Response samlResponse = new Response();
// Assign the consumer service url.
samlResponse.Destination = ConsumerServiceUrl;
Issuer issuer = new Issuer(GetAbsoluteUrl("~/"));
samlResponse.Issuer = issuer;
samlResponse.Status = new Status(SamlPrimaryStatusCode.Success, null);
Assertion samlAssertion = new Assertion();
samlAssertion.Issuer = issuer;
// Use the local user's local identity.
Subject subject = new Subject(new NameId(User.Identity.Name));
SubjectConfirmation subjectConfirmation = new SubjectConfirmation(SamlSubjectConfirmationMethod.Bearer);
SubjectConfirmationData subjectConfirmationData = new SubjectConfirmationData();
subjectConfirmationData.Recipient = ConsumerServiceUrl;
subjectConfirmation.SubjectConfirmationData = subjectConfirmationData;
subject.SubjectConfirmations.Add(subjectConfirmation);
samlAssertion.Subject = subject;
// Create a new authentication statement.
AuthnStatement authnStatement = new AuthnStatement();
authnStatement.AuthnContext = new AuthnContext();
authnStatement.AuthnContext.AuthnContextClassRef = new AuthnContextClassRef(SamlAuthenticationContext.Password);
samlAssertion.Statements.Add(authnStatement);
X509Certificate2 encryptingCert = new X509Certificate2(Path.Combine(HttpRuntime.AppDomainAppPath, "my-bank1-public.cer"));
EncryptedAssertion encryptedSamlAssertion = new EncryptedAssertion(samlAssertion, encryptingCert, new EncryptionMethod(SamlKeyAlgorithm.TripleDesCbc));
samlResponse.Assertions.Add(encryptedSamlAssertion);
samlResponse.Assertions.Add(samlAssertion);
samlResponse.SendHttpPost(Response.OutputStream, ConsumerServiceUrl, "10");
}